Is a page contiguous in the virtual address space or physical memory or both? Wikipedia says that: > A page, memory page, or virtual page is a fixed-length **contiguous** block of virtual memory, described by a single entry in the page table. It is the smallest unit of data for memory allocation performed by the operating system on behalf of a program, and for transfers between the main memory and any other auxiliary store, such as a hard disk drive. Is a page contiguous in the virtual address space or physical memory or both? Thanks.

Both. A page is the smallest unit of memory that the hardware page mapping function of the CPU deals with. If for example, pages are 4096 bytes in size, then each page begins and ends on a boundary aligned to 4096 bytes in both physical and virtual memory and all 4096 bytes in the page are mapped linearly and contiguously from virtual address to physical address within the page. Only at page boundaries can eb mapping "jump around".